Our research program features two objectives. The first is to examine the loss of visual capacities accompanying intoxication with the visual system poisons such as methylmercury and methanol. A comparison of the time course of these losses with physiological and pathological changes in the visual system will lead to: (1) a more complete grasp of the mechanisms of visual system toxicity and (2) the development of more sensitive visual screening tests for the monitoring of high risk populations. We emphasize early detection of impairment. Our second goal is the development of visual tests for monitoring toxic impairment of the CNS not specific to the visual system. Such tests must be sensitive, and easily administered as well as capable of distinguishing visual from non-visual impairment. We will begin with a comparison of the visual effects of intoxication with toluene vapor, nitrous oxide, and sodium amytal.